The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Generally, an EGR cooler functions to reduce the temperature of exhaust gas in a process of recirculating vehicle exhaust gas to a suction system. Exhaust gas that is introduced into a cylinder via an inlet manifold of an engine after passing an EGR cooler is processed by reburning. Through the reburning of exhaust gas, nitrogen oxides (NOx) in exhaust gas are burnt, and the content of hazardous substances in exhaust gas finally discharged to the outside of a vehicle is reduced.
A conventional EGR cooler includes a housing in which cooling water flows, and a heat radiation fin unit placed in the housing such that the fin unit is spaced apart from a cooling water flow path. In operation of the EGR cooler, high temperature exhaust gas flows in the heat radiation fin unit, and the cooling water flows in the housing. Thus, in the operation of the EGR cooler, the temperature of the exhaust gas is reduced and the temperature of the cooling water is increased due to heat exchange between the cooling water and the exhaust gas.
In case of a buried type EGR cooler inserted into an engine cylinder block, the gas passage is required to be bent at a predetermined angle so as to correspond to the shape of a cooling water flow path of a cylinder block. However, we have discovered that if the gas passage is bent so as to correspond to the shape of the cooling water flow path, damage to a heat radiation fin provided in the gas passage may occur.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art.